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-rw-r--r--sysdeps/tile/tilepro/strlen.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/sysdeps/tile/tilepro/strlen.c b/sysdeps/tile/tilepro/strlen.c
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+++ b/sysdeps/tile/tilepro/strlen.c
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+/* Copyright (C) 2011-2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <string.h>
+#include <stdint.h>
+
+size_t
+strlen (const char *s)
+{
+ /* Get an aligned pointer. */
+ const uintptr_t s_int = (uintptr_t) s;
+ const uint32_t *p = (const uint32_t *) (s_int & -4);
+
+ /* Read the first word, but force bytes before the string to be nonzero.
+ This expression works because we know shift counts are taken mod 32. */
+ uint32_t v = *p | ((1 << (s_int << 3)) - 1);
+
+ uint32_t bits;
+ while ((bits = __insn_seqb (v, 0)) == 0)
+ v = *++p;
+
+ return ((const char *) p) + (__insn_ctz (bits) >> 3) - s;
+}
+libc_hidden_builtin_def (strlen)